Tablet classification machine

ABSTRACT

A tablet classification machine has a drum having an inlet end and an outlet end, mounted for rotation and having circular openings having a predetermined diameter to pass tablets having a diameter less than a predetermined diameter and pieces of broken tablets. A tablet supply chute supplies tablets to the inlet end of the drum. A helical blade secured to the interior of the drum advances tablets from the inlet end to the outlet end of the drum. A first classification slide has its upper end below the outlet end of the drum to receive tablets discharged at the outlet end of the drum. The slide has parallel bars spaced apart a predetermined distance to provide for the passage therethrough of tablets having not more than a predetermined maximum thickness. A second classification slide below the first classification slide has parallel bars spaced apart a predetermined distance which is less than the distance between the bars of the first slide in order to retain tablets having more than a predetermined minimum thickness. A chute below the first slide and above the second slide collects tablets passing through the first slide and discharges them adjacent the upper end of the second slide.

United States Patent '91 Mlodzinski 1 Jan. 9, 1973 22 Filed:

[54] TABLET CLASSIFICATION MACHINE {75] Inventor: John J. Mlodzlnski,Willow Grove,

[73] Assignee: Smith Kline 8t French Laboratories,

Philadelphia, Pa.

Sept. 30, 1971 [2]] App]. No.: 185,141

[52] US. Cl. ..209/75, 209/95, 209/99 [51] Int. Cl ..B07c 5/04 [58]Field of Search ..209/95, 75, 86, 97, 99, 107

[56] References Cited UNITED STATES PATENTS 3,612,273 10/1971 Pritchett..209/95 3,347,368 10/1967 Mogensen ..209/99 Primary Examiner-Richard A.Schacher Assistant ExaminerGene A. Church Attorney-Smith, Harding,Earley & Follmer [57] ABSTRACT A tablet classification machine has adrum having an inlet end and an outlet end, mounted for rotation andhaving circular openings having a predetermined diameter to pass tabletshaving a diameter less than a predetermined diameter and pieces ofbroken tablets. A tablet supply chute supplies tablets to the inlet endof the drum. A helical blade secured to the interior of the drumadvances tablets from the inlet end to the outlet end of the drum. Afirst'cla'ssification slide has its upper end below the outlet end ofthe drum to receive tablets discharged at theoutlet end of the drum. Theslide has parallel bars spaced apart a predetermined distance to providefor the passage therethrough of tablets having not more than apredetermined maximum thickness. A second classification slide below thefirst classification slide has parallel bars spaced apart apredetermined distance which is less than the distance between the barsof the first slide in order to retain tablets having more than apredetermined minimum thickness. A chute below the first slide and abovethe second slide collects tablets passing through the first slide anddischarges them adjacent the upper end of the second slide.

7 Claims, 7 Drawing Figures r; on M, M, c we, was

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sum u or 4 INVENTOR JOHN J. MLODZINSKI ATTORNEYS TABLET CLASSIFICATIONMACHINE BACKGROUND OF THE INVENTION In the process of manufacturingpharmaceutical tablets variations in the diameter and thickness of thetablets result. Generally, it is desired to package for sale only thetablets which fall within ranges of diameters and thicknesses which areexceeded by some of the tablets. Thus, it is necessary to eliminate thetablets which exceed these ranges. The machine of this inventionprovides a rapid means for classifying tablets to eliminate the tabletsoutside of the desired ranges and pieces of broken tablets at very smallcost.

SUMMARY OF THE INVENTION A tablet classification machine comprises adrum having an inlet end and an outlet end, mounted for rotation, andhaving circular openings having a predetermined diameter to passtherethrough tablets having a diameter less than a predetermined minimumdiameter and pieces of broken tablets. The drum is rotated on its axis.A first classification slide has its upper end below the outlet end ofthe drum to receive tablets having at least the predetermined minimumdiameter. The first slide has parallel bars spaced apart a predetermineddistance to permit passage therethrough of tablets having less than apredetermined thickness to a second classification slide positionedbelow the first classification slide. The second classification slidehas parallel bars spaced apart a predetermined distance which is lessthan the distance between the bars of the first slide to retain tabletshaving more than a predetermined thickness. In this manner only tabletswithin a desired range of thickness are selected. A chute mounted belowthe first slide and above the second slide collects tablets passingthrough the first slide and discharges them adjacent the upper end ofthe second slide.

DESCRIPTION OF THE DRAWINGS FIG. 1 is a front elevation of a tabletclassification machine in accordance with the invention;

FIG. 2 is a vertical section, partially broken away, of the machine ofFIG. 1;

FIG. 3 is a top plan view of the machine of FIG. 1;

FIG. 4 is a top plan view of the upper classification slide of themachine of FIG. 1;

FIG. 5 is a section taken on the plane indicated by the line 5--5 inFIG. 4;

FIG. 6 is a section, partially broken away, taken on the plane indicatedby the line 66 in FIG. 2, and

FIG. 7 is a section, partially broken away, taken on the plane indicatedby the line 7-7 in FIG. 2.

PREFERRED EMBODIMENT Referring first to FIG. 1, a tablet classificationmachine 2 in accordance with the invention has a supporting framework 4.A drum 6 has its major portion perforated with openings 8 which arecircular and of the same diameter which is selected so as to retainwithin the drum tablets having a diameter greater than a predeterminedminimum diameter. Openings 8 are of primary importance in permittingpieces of broken tablets to pass therethrough out of the drum. Drum 6has ring portions 10 and 12 which rest on idler rollers l4 and 16 and 18and 20 respectively (FIG. 3), these dicated at 30.

Tablets are supplied to drum 6 from a hopper 34 which is mounted on andcommunicates with a slide 36 which discharges into the interior of drum6 as best seen in FIG. 2. Slide 36 is mounted on a vibrator 38 to causetablets to advance along the slide into drum 6 in a conventional manner.

A chute 40 is positioned below drum 6 to catch tablets and pieces ofbroken tablets falling through openings 8. Chute 40 discharges into asecond chute 42 which in turn discharges into a waste container 44mounted on a platform 45.

Deflector plates 46 and 48 attached to frame 4 on either side of drum 6act to guide particles passing through openings 8 in drum 6 into chute40.

Drum 6 has secured to its interior surface a helical blade 52 which, asthe drum rotates clockwise as viewed from the right hand end of FIG. 2,advances tablets from the inlet end of the drum 6 to the outlet endwhere the discharged tablets fall onto spaced bars 54 secured toU-shaped member 56. The bars 54 allow free passage of the tablets andserve to spread the tablets over a wide area.

Tablets passing through spaced bars 54 drop onto slide 58 which hasspaced parallel round bars 62 secured as by welding to support members64 and 66 which in turn are mounted on brackets 68 and 70 secured to aframe 71 slideably mounted on brackets 71A and 718 secured respectivelyto walls 72 and 74. Slide 58 extends from a point adjacent wall 72 to apoint adjacent wall 74. A panel member 76 welded to the rearmost bar 62fills the gap between the rearmost bar 62 and rear wall 78. Similarly, apanel member 76 (FIG. 4) welded to the frontmost bar 62 fills the gapbetween the frontmost bar 62 and access door 82 which, as shown in FIG.3, is hinged to wall 72 at 84.

Bars 62 are spaced apart to provide for the passage therethrough oftablets 86 having not more than a predetermined maximum desiredthickness (FIG. 6). The retained tablets slide downwardly and gatheradjacent gate 88. When a substantial pile of retained tablets hasaccumulated, gate 88 is raised by means of handle portion 90 (FIG. 6)and the tablets pass to waste container 91 contained in housing 92.Container 90 has a front panel 94 which completely closes off the frontopening of housing 92 and is provided with a knob 96 to facilitate theremoval of container 91 (FIG. 1).

A slide plate 100 catches tablets passing through slide 58 anddischarges them adjacent the upper end of a slide 102 which has spacedparallel round bars 104 secured as by welding to support members 106 and108 which in turn are supported on brackets 110 and 112 respectively,slide 102 extending from adjacent wall 74 to a point adjacent wall 72which is provided with a discharge opening 114 for the passage oftablets retained on slide 102. Brackets 110 and 112 are secured to frame115 which is slideably mounted on brackets 115A and 1158 securedrespectively to walls 72 and 74. Bars 104 are spaced closer togetherthan are bars 62, the distance between bars 104 being selected to retaintablets having more than predetermined minimum thickness. in a mannersimilar to slide 58, slide 102 has panel members 76 (FIG. 7) at thefront and back to fill in the gaps adjacent rear wall 78 and door 82.

The tablets passing through slide 102 are caught in a waste container116 which can be removed for emptying when door 82 is opened. Thetablets retained on slide 102 passing through opening 114 drop intochute 120 which discharges the tablets onto a belt conveyor 122. Adeflector cover 124 is mounted above chute 120 adjacent to opening 114.

By way of a typical example openings 8 may have a diameter of 0.375inch, bars 62 may be spaced apart 0.240 inch, and bars 104 may be spacedapart 0.187 inch.

The operation of the above described machine is obvious from theforegoing description. The embodiment described is illustrative and isnot intended to be limiting.

1 claim:

1. A tablet classification machine comprising:

a drum having an inlet end and an outlet end, mounted for rotation andhaving circular openings having a predetermined diameter to retain'tablets having a predetermined minimum diameter and pass through smallermaterial,

means to rotate the drum,

means to supply tablets to the inlet end of the drum,

a first classification slide having its upper end below the outlet endof the drum to receivetablets having the said predetermined minimumdiameter, said slide comprising parallel bars spaced apart apredetermined distance to pass through tablets having less than apredetermined thickness, and

a second classification slide below the first classification slide toreceive tablets passing through the first classification slide, saidsecond slide comprising parallel bars spaced apart a predetermineddistance which is less than the distance between the bars of the firstslide to retain tablets having more than a predetermined thickness, and

a chute below the first slide and above the second slide to collecttablets passing through the first slide and discharge them adjacent theupper end of the second slide.

2..A machine in accordance with claim 1 in which the parallel bars ofboth slides are round.

3. A machine in accordance with claim 2 in which a helical blade issecured to the interior of the drum to advance tablets from the inletend to the outlet end of the drum.

4. A machine in accordance with claim 1 in which a helical blade issecured to the interior of the drum to advance tablets from the inletend to the outlet end of the drum.

5. A machine in accordance with claim- 4 having spaced parallel barsadjacent and below the outlet end of the drum to spread out the tabletsdischarged from the drum. I

6. A machine in accordance with claim 1 in which the drum is mounted forrotation on idler rollers, and the means to rotate the drum includes aring gear secured to the drum and a driven gear engaging the bottom ofthe ring gear permitting the drum to be removed freely.

A machine in accordance with claim 1 having spaced parallel barsadjacent and below the outlet end of the drum to spread out the tabletsdischarged from the drum.

1. A tablet classification machine comprising: a drum having an inletend and an outlet end, mounted for rotation and having circular openingshaving a predetermined diameter to retain tablets having a predeterminedminimum diameter and pass through smaller material, means to rotate thedrum, means to supply tablets to the inlet end of the drum, a firstclassification slide having its upper end below the outlet end of thedrum to receive tablets having the said predetermined minimum diameter,said slide comprising parallel bars spaced apart a predetermineddistance to pass through tablets having less than a predeterminedthickness, and a second classification slide below the firstclassification slide to receive tablets passing through the firstclassification slide, said second slide comprising parallel bars spacedapart a predetermined distance which is less than the distance betweenthe bars of the first slide to retain tablets having more than apredetermined thickness, and a chute below the first slide and above thesecond slide to collect tablets passing through the first slide anddischarge them adjacent the upper end of the second slide.
 2. A machinein accordance with claim 1 in which the parallel bars of both slides areround.
 3. A machine in accordance with claim 2 in which a helical bladeis secured to the interior of the drum to advance tablets from the inletend to the outlet end of the drum.
 4. A machine in accordance with claim1 in which a helical blade is secured to the interior of the drum toadvance tablets from the inlet end to the outlet end of the drum.
 5. Amachine in accordance with claim 4 having spaced parallel bars adjacentand below the outlet end of the drum to spread out the tabletsdischarged from the drum.
 6. A machine in accordance with claim 1 inwhich the drum is mounted for rotation on idler rollers, and the meansto rotate the drum includes a ring gear secured to the drum and a drivengear engaging the bottom of the ring gear permitting the drum to beremoved freely.
 7. A machine in accordance with claim 1 having spacedparallel bars adjacent and below the outlet end of the drum to spreadout the tablets discharged from the drum.